Head-mounted display

ABSTRACT

A head-mounted display configured to enhance the ease of wearing work and the stability of wearing is provided. A wearing band has an extending section and a movable section that is movable relative to the extending section in the length direction of the wearing band. A locking mechanism M is capable of switching the wearing band between an unlocked state in which the movements of the movable section in the extending direction in which the length of the wearing band is increased and in the retracting direction in which the length of the wearing band is decreased are allowed and a locked state in which the movement of the movable section in the extending direction is restricted. The movable section is urged at least in the retracting direction in an unlocked state.

TECHNICAL FIELD

The present invention relates to a head-mounted display.

BACKGROUND ART

The development of head-mounted displays that are used as worn on theheads of users have been under way (hereafter a head-mounted displaywill be referred to as an HMD). An HMD has a main body that has adisplay to be arranged in front of the eyes of the user and a wearingband that fixes the main body onto the head of the user (refer to JP1997-304724A, for example).

SUMMARY Technical Problem

Some HMDs have a mechanism of adjusting the length of the wearing bandthereof. When the user adjusts the length of the wearing band to thesize of his or her head, the HMD is supported on the head withstability. However, conventional HMDs have a problem that it iscumbersome for users to execute the adjustment of the length of wearingbands. For example, if a user attempts to adjust the length of thewearing band with the HMD worn on the head of the user, the position andorientation of the HMD may change during the adjusting activity, therebymaking it complicated to do the adjustment.

An object of the present disclosure is to propose a head-mounted displayconfigured to enhance the ease of wearing work and the stability ofwearing.

Solution to Problem

A head-mounted display proposed by the present disclosure includes amain body in which a display is built, a wearing band extending from themain body to a rear side and having a shape enclosing a head of a useras a whole, a movable section configured to make up a part of thewearing band, link with another part of the wearing band in a lengthdirection of the wearing band, and be movable relative to the anotherpart of the wearing band in a retracting direction in which the lengthof the wearing band is decreased and in an extending direction in whichthe length of the wearing band is increased, and a locking mechanismcapable of switching the wearing band between an unlocked state in whichmovements of the movable section in the extending direction and theretracting direction are allowed and a locked state in which a movementof the movable section at least in the extending direction isrestricted. The movable section may be urged at least in the retractingdirection in the unlocked state.

Further, a head-mounted display proposed by the present disclosureincludes a main body in which a display is built, a wearing bandextending from the main body to a rear side and having a shape enclosinga head of a user as a whole, a movable section configured to make up apart of the wearing band, link with another part of the wearing band ina length direction of the wearing band, and be movable relative to theanother part of the wearing band in a retracting direction in which thelength of the wearing band is decreased and in an extending direction inwhich the length of the wearing band is increased, and a lockingmechanism capable of switching the wearing band between an unlockedstate in which movements of the movable section in the extendingdirection and the retracting direction are allowed and a locked state inwhich a movement of the movable section at least in the extendingdirection is restricted. The locking mechanism may switch the wearingband from the unlocked state to the locked state when the movablesection moves in the retracting direction.

According to the head-mounted display practiced as one embodiment of thepresent disclosure, the ease of wearing work and the stability ofwearing are enhanced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating a head-mounted displaypracticed as one embodiment of the present invention.

FIG. 2 is a side view of the head-mounted display.

FIG. 3 is a plan view of the head-mounted display.

FIG. 4 is a rear view of a movable section of the head-mounted display.

FIG. 5 is a diagram illustrating an internal structure of a movablesection arranged on a wearing band.

FIG. 6 is a cross-sectional diagram illustrating a locking mechanism, acut surface thereof taken along line VI-VI depicted in FIG. 4.

FIG. 7 is a diagram illustrating a movement of a clutch member making upthe locking mechanism.

FIG. 8 is a cross-sectional view illustrating a first manipulatingmember taken along line VIII-VIII depicted in FIG. 6.

FIG. 9 is a diagram viewing a clutch stopper and the first manipulatingmember making up the locking mechanism in the direction of an axialline.

FIG. 10 is an expanded view indicative of a movement of the clutchstopper. In this diagram, the clutch stopper is partially fractured.

FIG. 11 is a cross-sectional view of one variation to the lockingmechanism.

FIG. 12 is a schematic view for describing a movement of the clutchmember depicted in FIG. 11, indicating a part of a gear section such asa link member.

FIG. 13 is a plan view illustrating a structure that allows a relativemovement between the main body and the wearing band.

FIG. 14 is a side view illustrating a structure that allows a relativemovement between the main body and the wearing band.

FIG. 15 is a cross-sectional view illustrating a structure that allows arelative movement between the main body and the wearing band. Thisdiagram is a cross-sectional view taken along line XV-XV depicted inFIG. 14.

FIG. 16 is a diagram illustrating an example of a structure that allowsthe adjustment of an angle of a front pad.

FIG. 17 is a perspective view illustrating the main body of thehead-mounted display viewed from the rear side.

DESCRIPTION OF EMBODIMENT

The following describes one embodiment of the present invention withreference to drawings. FIG. 1 through FIG. 3 illustrate a head-mounteddisplay 1 practiced as one embodiment of the present invention(hereafter the head-mounted display will be referred to as an “HMD”).FIG. 1 is a perspective view, FIG. 2 is a side view, and FIG. 3 is aplan view. In FIG. 2, a front support section 23 to be described lateris partially fractured.

In the description below, it is assumed that Y1 and Y2 depicted in thesediagrams be a forward direction and a backward direction, respectively;X1 and X2 be a right direction and a left direction, respectively. Also,it is assumed that Z1 and Z2 be an upward direction and a downwarddirection, respectively.

The HMD 1 has a main body 10 in which a display 11 (refer to FIG. 2) isbuilt in the front side. In one example of the HMD 1, the display 11displays a three-dimensional video image. A video image that isdisplayed by the display 11 may be a two-dimensional video image. As thedisplay 11, a liquid crystal display device or an organicelectroluminescence (EL) display device may be used. The type of thedisplay 11 is not limited to these. The main body 10 includes a housing14 and the display 11 is housed in the housing 14.

As depicted in FIG. 1, the HMD 1 has a wearing band 20 for being worn onthe head of a user. The wearing band 20 is shaped such that the wearingband 20 extends from the main body 10 toward the rear side, therebytotally surrounding the head of the user. In other words, the wearingband 20 is circular in a plan view and, when the HMD 1 is in use, therear part of the wearing band 20 is set to the rear side of the head. Inone example, the wearing band 20 is connected to an upper part of themain body 10 and extends from the upper part of the main body 10 towardthe rear side. The wearing band 20 may be connected to right-end sectionand a left-end section of the main body 10. As depicted in FIG. 2, thewearing band 20 may extend toward the rear side and, at the same time,tilt toward the down side.

As depicted in FIG. 2, the wearing band 20 has, at one part thereof, amovable section 30. The movable section 30 links to another part of thewearing band 20 in the length direction of the wearing band 20. Then,the movable section 30 is relatively movable for another part of thewearing band 20 in the direction in which the length of the wearing band20 is shortened and in the direction in which the length of the wearingband 20 is increased (hereafter, the direction in which the length ofthe wearing band 20 is shortened is referred to as “retractingdirection” and the direction in which the length of the wearing band 20is increased is referred to as “extending direction”).

As depicted in FIG. 2, the wearing band 20 has an extending section 24extending from the front side to the rear side of the wearing band 20.The movable section 30 is linked to the rear section of the extendingsection 24 in the direction along the length of the wearing band 20. Tobe more specific, the rear section of the extending section 24 is matedin a housing 30 a through a hole formed at an end of the housing 30 athat makes up the movable section 30. The movable section 30 is capableof relatively moving for the extending section 24 in the extendingdirection and the retracting direction. In FIG. 2, the extendingdirection is denoted by a symbol D2 and the retracting direction isdenoted by a symbol D1. By moving the movable section 30, the user isable to adjust the length of the wearing band 20.

The wearing band 20 has, on the front side thereof, the front supportsection 23 connected to the upper part of the main body 10. As depictedin FIG. 3, the wearing band 20 has two extending sections 24. The twoextending sections 24 individually extend from a right-side part and aleft-side part of the front support section 23 toward the rear side. Themovable section 30 is positioned between the rear parts of the twoextending sections 24, thereby forming a rear-side part of the wearingband 20. Therefore, when the HMD 1 is in use, the movable section 30 isset to the rear side of the head of the user. When the HMD 1 is in use,the wearing band 20 holds the head of the user in the forward-backwarddirection with the front support section 23 and the movable section 30.The movable section 30 relatively moves in the retracting direction forboth of the two extending sections 24, thereby moving to the front side.The movable section 30 relatively moves in the extending direction forboth of the two extending sections 24, thereby moving to the rear side.

The front support section 23 and the extending section 24 are made of amaterial comparatively high in stiffness such as plastic, for example.Also, the movable section 30 is made of a material comparatively high instiffness such as plastic, for example. The movable section 30 may bearranged with a cushion 30 b (refer to FIG. 1) that is applied to therear side of the head. Also, the front support section 23 may bearranged with a cushion 25 b (refer to FIG. 2) that is applied to thefront side of the head.

The structure of the wearing band 20 is not restricted to the exampledescribed above. For example, the movable section 30 may not berelatively movable for one of the two extending sections 24. Also, thewearing band 20 may not always have the front support section 23. Inthis case, the extending section 24 may extend from the right-side partor the left-side part of the main body 10 to the rear side, for example.

The wearing band 20 has a locking mechanism M configured to switch thewearing band 20 between a locked state and an unlocked state (thelocking mechanism M is built in the movable section 30 as will bedescribed later (refer to FIG. 6)). In the unlocked state, the movementof the movable section 30 in the extending and retracting directions areallowed. In the locked state, the movement of the movable section 30 inthe extending direction is restricted. That is, in the unlocked state,both the increase and decrease in the length of the wearing band 20 areallowed. In the locked state, the increase in the length of the wearingband 20 is restricted.

As described above, the movable section 30 is relatively movable forboth of the two extending sections 24. In this case, in the unlockedstate, the movable section 30 can be moved to both the front and rearsides; in the unlocked state, the movement of the movable section 30 tothe rear side is restricted. In one example, when the wearing band 20 isin the locked state, the movement of the movable section 30 in theretracting direction is allowed. In another example, when the wearingband 20 is in the locked state, the movements of the movable section 30in both the extending and retracting directions may be restricted.Details of the locking mechanism M will be described later.

As depicted in FIG. 3, the wearing band 20 has an elastic member 26 thatcauses elasticity acting on the movable section 30 in the retractingdirection. The movable section 30 is urged in the retracting directionby the elasticity of the elastic member 26. The movable section 30 isurged in the retracting direction in both the locked state and theunlocked state. The elastic member 26 is a rubber band, for example.Therefore, as the length of the wearing band 20 increases, theelasticity (or an urge force) of the elastic member 26 to the movablesection 30 increases. The elastic member 26 may be a spring.

The wearing band 20 with the movable section 30 urged and the lockingmechanism M make the wearing work of the HMD 1 easy. In other words,when the user wears the wearing band 20 in the unlocked state onto thehead, the wearing band 20 is temporarily fixed (or temporarily worn) onthe head because the movable section 30 is urged in the retractingdirection. Therefore, with the wearing band 20 temporarily fixed, theuser is able to adjust the length of the wearing band 20, namely, adjustthe position of the movable section 30. When the positional adjustmentof the movable section 30 has been completed, the user is able to stablyfix (or wear) the wearing band 20 on the head by putting the wearingband 20 in the locked state. It should be noted that, in the lockedstate, the movable section 30 may not be urged in the retractingdirection. Also, in this case, the wearing work is facilitated.

As described above, the wearing band 20 has the extending section 24that extends in the length direction of the wearing band 20. Theextending section 24 extends from the front side (to be more specific,the front support section 23) of the wearing band 20 to the rear side.As depicted in FIG. 3, the elastic member 26 also extends in the lengthdirection of the wearing band 20. To be more specific, the elasticmember 26 also extends from the front side to the rear side of thewearing band 20. The elastic member 26 is arranged along the extendingsection 24. A rear part of the elastic member 26 is attached to themovable section 30 and the elastic member 26 pulls the movable section30 in the retracting direction of the wearing band 20. That is, theelastic member 26 pulls the movable section 30 to the front side.According to the elastic member 26 as described above, the movablesection 30 can be urged to the front side with a simple structure.

As described above, the wearing band 20 has the two extending sections24 that individually extend from the right-side part and the left-sidepart of the front support section 23 toward the rear side. As depictedin FIG. 3, the wearing band 20 has two elastic members 26. As with theextending sections 24, the two elastic members 26 individually extendfrom the right-side part and the left-side part of the front supportsection 23 toward the rear side and arranged along the two extendingsections 24. The elastic members 26 are arranged inside the twoextending sections 24, for example. A front end of the elastic member 26is fixed inside a mounting section 23 a arranged in each of the rightside and the left side of the front support section 23, for example. Arear end of the elastic member 26 is attached to the movable section 30.For example, the rear end of the elastic member 26 is mated in thehousing 30 a through a hole formed in the housing 30 a of the movablesection 30 to be fixed inside the housing 30 a. The movable section 30is pulled by the two elastic members 26 to the front side.

The structure of the elastic member 26 is not restricted to thatdescribed above. For example, the elastic member 26 may be a spring. Ifa spring is used for the elastic member 26, the elastic member 26 maynot be arranged along the extending section 24. For example, the elasticmember (spring) 26 may be arranged inside the housing 30 a of themovable section 30. In this case, the elastic member 26 may exert anelastic force that pulls the rear section of the extending section 24mated inside the housing 30 a. For example, the elastic member 26arranged inside the housing 30 a may directly pull the rear section ofthe extending section 24. Further, the elastic member 26 may rotate alink member 31 (refer to FIG. 5) of the locking mechanism M to bedescribed later in the direction in which the length of the wearing band20 is shortened. Also, in these structures, a force that acts on themovable section 30 in the retracting direction can be obtained.

The following describes the locking mechanism M. FIG. 4 is a rear viewof the movable section 30. FIG. 5 illustrates an internal structure ofthe movable section 30. In FIG. 5, a rack 24 a arranged at the rearsection of the extending section 24 and the link member 31 are depicted.FIG. 6 is a cross-sectional diagram illustrating the locking mechanismM, a cut surface thereof taken along line VI-VI depicted in FIG. 4. FIG.7 is a diagram illustrating a movement of a clutch member 32 making upthe locking mechanism M. FIG. 8 is a cross-sectional view illustrating afirst manipulating member 34 taken along line VIII-VIII depicted in FIG.6. FIG. 8 illustrates a stopper 33 and the first manipulating member 34that make up the locking mechanism M. FIG. 9 is a diagram viewing aclutch stopper 35 and the first manipulating member 34 making up thelocking mechanism M in the direction of an axial line C1. FIG. 10 is anexpanded view indicative of a movement of the clutch stopper 35. In FIG.10, the clutch stopper 35 is partially fractured so as to indicate anengaging section 35 b to be described later.

As depicted in FIG. 5, the wearing band 20 has, inside the housing 30 a,the link member 31 that rotates along with the movement of the movablesection 30 in the retracting direction and the extending direction. Inthe example depicted in FIG. 5, the link member 31 rotates clockwisealong with the movement of the movable section 30 in the retractingdirection. Conversely, the link member 31 rotates counterclockwise alongwith the movement of the movable section 30 in the extending direction.In what follows, the rotational direction of the link member 31 in thecase where the movable section 30 moves in the retracting direction isreferred to as “retracting rotational direction.” The rotationaldirection of the link member 31 in the case where the movable section 30moves in the extending direction is referred to as “extending rotationaldirection.” For the link member 31, the retracting rotational directioncorresponds to a “third direction” in the claims hereof; for the linkmember 31, the extending rotational direction corresponds to a “fourthdirection” of the claims hereof. The link member 31 is supported by anaxis section 38 a (refer to FIG. 6) formed on a frame 38 accommodated inthe housing 30 a, for example.

As described above, the extending section 24 has, at the rear sectionthereof, the rack 24 a extending in the length direction of the wearingband 20. As depicted in FIG. 5, a gear section 31 a of the link member31 engages with the rack 24 a. Therefore, the link member 31 rotatesalong with a relative movement between the rack 24 a and the movablesection 30.

As depicted in FIG. 5, the racks 24 a of the two extending sections 24are positioned away from each other in the up-down direction. The linkmember 31, positioned between the two racks 24 a, are engaged with bothof the two racks 24 a. According to this structure, a relative movementdistance between the right-side extending section 24 and the movablesection 30 is equal to a relative movement distance between theleft-side extending section 24 and the movable section 30. As a result,the movable section 30 moves in the forward-backward direction inparallel. As will be described later, in the unlocked state, the lockingmechanism M allows the link member 31 to rotate in both of thedirections; the extending rotational direction and the retractingrotational direction. On the other hand, in the locked state, therotation of the link member 31 in the extending rotational direction isrestricted.

It should be noted that, in the example depicted in FIG. 5, theleft-side rack 24 a is positioned over the gear section 31 a of the linkmember 31 and the right-side rack 24 a is positioned under the gearsection 31 a of the link member 31. However, the positional relation ofthe two racks 24 a may be reversed. In such a case, the link member 31rotates counterclockwise along with a movement of the movable section 30in the retracting direction and rotates clockwise along with a movementof the movable section 30 in the extending direction (in this case, thecounterclockwise direction is the retracting rotational direction andthe clockwise direction is the extending rotational direction).

As depicted in FIG. 6, the locking mechanism M has the firstmanipulating member 34. The first manipulating member 34 is rotationallysupported. Also, the first manipulating member 34 is arranged on theaxial line C1 that is common to the link member 31. The firstmanipulating member 34 has a manipulating section 34 a. The uppersection of the manipulating section 34 a is exposed from an openingformed on the upper surface of the housing 30 a of the movable section30 (refer to FIG. 4). In addition, the lower section of the manipulatingsection 34 a is exposed from an opening formed on the lower surface ofthe housing 30 a of the movable section 30 (refer to FIG. 4). Hence, theuser is able to manipulate the first manipulating member 34. That is, bymoving the upper section and the lower section of the manipulatingsection 34 a in the opposite directions, the user is able to rotate thefirst manipulating member 34.

The locking mechanism M allows the rotation of the first manipulatingmember 34 in the retracting rotational direction and restricts therotation of the first manipulating member 34 in the extending rotationaldirection. In one example, as depicted in FIG. 8, the locking mechanismM has the stopper 33 that restricts the rotational direction of thefirst manipulating member 34 to the retracting rotational direction. Thefirst manipulating member 34 has a gear section 34 d and the stopper 33has an engaging section 33 a that engages with the gear section 34 d.The engagement between the gear section 34 d and the engaging section 33a restricts the rotational direction of the first manipulating member 34to the retracting rotational direction. In other words, it so set thatthe shape of each gear making up the gear section 34 d and the shape ofthe engaging section 33 a allow the rotation of the first manipulatingmember 34 in the retracting rotational direction and restrict therotation in the extending rotational direction. The stopper 33 is urgedto the gear section 34 d side with a spring (not depicted), for examplesuch that the engaging section 33 a is engaged with the gear section 34d. Here, for the first manipulating member 34, the retracting rotationaldirection corresponds to a “first direction” in the claims hereof; forthe first manipulating member 34, the extending rotational directioncorresponds to a “second direction” in the claims hereof. The structurein which the rotational direction of the first manipulating member 34 islimited is not necessarily limited to the structure described above;namely, this structure may be changed as required.

In the locked state, the locking mechanism M links the link member 31with the first manipulating member 34; in the unlocked state, thelocking mechanism M releases the linkage between the link member 31 andthe first manipulating member 34. This setup allows the movement of themovable section 30 in both the retracting direction and the extendingdirection in the unlocked state and restricts the movement of themovable section 30 in the extending direction in the locked state.Further, in the locked state, the movement of the movable section 30 inthe retracting direction is allowed.

In the present embodiment, the locking mechanism M links the link member31 with the first manipulating member 34 when the first manipulatingmember 34 moves in the retracting rotational direction. In other words,when the first manipulating member 34 rotates in the retractingrotational direction, the locking mechanism M links the link member 31with the first manipulating member 34 such that these members rotate inan integrated manner. According to this structure, the movable section30 moves in the retracting direction when the user rotates the firstmanipulating member 34 in the retracting rotational direction. At thesame time, the wearing band 20 enters a locked state, therebyrestricting the movable section 30 from moving in the extendingdirection. That is, the adjustment of the length of the wearing band 20(the positional adjustment of the movable section 30) and the shiftingof the wearing band 20 to the locked state are realized by a singlemanipulation by the user.

In one example, as depicted in FIG. 6, the locking mechanism M has theclutch member 32 for controlling the linkage between the link member 31and the first manipulating member 34. The clutch member 32 is movablebetween a locked position and an unlocked position (in FIG. 7(a), theclutch member 32 is arranged at the unlocked position; in FIG. 7(b), theclutch member 32 is arranged at the locked position). At the lockedposition, the clutch member 32 is engaged with both the link member 31and the first manipulating member 34. Hence, when the clutch member 32is at the locked position, the link member 31 is indirectly linked withthe first manipulating member 34 through the clutch member 32. At theunlocked position, the clutch member 32 is not engaged with at least oneof the link member 31 and the first manipulating member 34. Hence, whenthe clutch member 32 is at the unlocked position, the linkage betweenthe link member 31 and the first manipulating member 34 is released. Itshould be noted that “the clutch member 32 is engaged” denotes that theclutch member 32 rotates with the link member 31 (or the firstmanipulating member 34) in an integrated manner and does not denote onlythe engagement with a gear or a spline which will be described later.

As depicted in FIG. 6, the clutch member 32, arranged on the axial lineC1 common to the link member 31 and the first manipulating member 34, isrotatable. In addition, the clutch member 32 is movable between thelocked position and the unlocked position along this axial line C1.

A depicted in FIG. 6, the link member 31 has a cylinder section 31 bthat extends in the axial line direction (“axial line direction” denotesthe extending direction of the axial line C1). The clutch member 32 iscircular in shape and mated on the outer side of the cylinder section 31b. On the outer circumferential surface of the cylinder section 31 b, aprojected section 31 c extending in the axial line direction is formed(refer to FIG. 5). On the inner circumferential surface of the clutchmember 32, a recessed section 32 b that engages with the projectedsection 31 c is formed (refer to FIG. 9). The clutch member 32 moves inthe axial line direction as engaged with the outer circumferentialsurface of the cylinder section 31 b.

Further, as depicted in FIG. 6, the clutch member 32 has a gear section32 a on the outer circumferential section thereof. The firstmanipulating member 34 is circular in shape and has a gear section 34 bon the inner circumferential surface thereof. The clutch member 32 ispositioned between the link member 31 and the first manipulating member34 in the axial line direction. The clutch member 32 is arranged insidethe first manipulating member 34 with the gear section 32 a beingcapable of engaging with the gear section 34 b of the first manipulatingmember 34.

As depicted in FIG. 7(a), at the unlocked position, the clutch member 32is arranged closer to the link member 31. At this moment, the gearsection 32 a of the clutch member 32 is disengaged from the gear section34 b of the first manipulating member 34. In other words, although theclutch member 32 is engaged with the link member 31, the clutch member32 is not engaged with the first manipulating member 34. As depicted inFIG. 7(b), at the locked position, the clutch member 32 is arrangedcloser to the first manipulating member 34. At this moment, the gearsection 32 a of the clutch member 32 is engaged with the gear section 34b of the first manipulating member 34. That is, the clutch member 32 isengaged with both the link member 31 and the first manipulating member34.

The positional relations and the engagement relations between the linkmember 31, the first manipulating member 34, and the clutch member 32are not restricted to those examples described above. For example,instead of the cylinder section 31 b of the link member 31, a cylindersection may be formed on the clutch member 32 with this cylinder sectionof which the link member 31 is engaged. Further, instead of the cylindersection 31 b of the link member 31, a cylinder section may be formed onthe first manipulating member 34 with this cylinder section of which theclutch member 32 is engaged.

The locking mechanism M of the present embodiment moves the clutchmember 32 from the unlocked position to the locked position when thefirst manipulating member 34 moves in the retracting rotationaldirection. As depicted in FIG. 9, the locking mechanism M has the clutchstopper 35 for controlling a position of the clutch member 32.

The clutch member 32 is urged to the locked position. As depicted inFIG. 7(a), in the unlocked state, the clutch stopper 35 (a stoppersection 35 a to be described later) restricts the movement of the clutchmember 32 to the locked position against the force acting on the clutchmember 32. The locking mechanism M clears the restriction imposed by theclutch stopper 35 when the first manipulating member 34 moves in theretracting rotational direction. As a result, as depicted in FIG. 7(b),the clutch member 32 moves to the locked position.

The locking mechanism M has a spring 37 (refer to FIG. 6) that urges theclutch member 32 from the unlocked position to the locked position. Thespring 37 is mated on the outside of the cylinder section 31 b of thelink member 31, for example. The spring 37 presses the clutch member 32toward the first manipulating member 34, namely, toward the lockedposition. As depicted in FIG. 9, the clutch stopper 35 has the stoppersection 35 a that restricts the movement of the clutch member 32 towardthe locked position. The stopper section 35 a abuts on an end section ofthe clutch member 32 inside the first manipulating member 34, therebyrestricting the movement of the clutch member 32 to the locked position.

The clutch stopper 35 is movable between a stopper acting position and astopper release position. The stopper acting position is a position ofthe clutch stopper 35 depicted in FIG. 10(a), for example. When theclutch stopper 35 is arranged at the stopper acting position, thestopper section 35 a abuts on the end section of the clutch member 32 inthe axial line direction, thereby restricting the movement of the clutchmember 32 to the locked position. The stopper release position is aposition of the clutch stopper 35 depicted in FIG. 10(b), for example.When the clutch stopper 35 is arranged at the stopper release position,the stopper section 35 a comes away from the clutch member 32, therebyallowing the clutch member 32 to move to the locked position.

The clutch stopper 35 is configured so as to move from the stopperacting position to the stopper release position when the firstmanipulating member 34 rotates in the retracting rotational direction.In one example, the clutch stopper 35 is supported such that the stoppersection 35 a moves in the radial direction of the first manipulatingmember 34 (namely, the radial direction of the clutch member 32). Then,in order to allow the clutch stopper 35 to move in the radial directionof the first manipulating member 34 along with the rotation of the firstmanipulating member 34, the clutch stopper 35 and the first manipulatingmember 34 are engaged with each other.

As depicted in FIG. 6 and FIG. 9, the first manipulating member 34 has agear section 34 c on the side surface of the side of the clutch stopper35. As depicted in FIG. 10, the clutch stopper 35 has the engagingsection 35 b. The engaging section 35 b is positioned outside of theradial direction of the gear section 34 c and engages with the gearsection 34 c. The clutch stopper 35 is supported so as to allow themovement of the stopper section 35 a and the engaging section 35 bdescribed above in the radial direction of the gear section 34 c. Thatis, the clutch stopper 35 is supported such that the stopper section 35a and the gear section 34 c are movable in the radial direction of thefirst manipulating member 34. An end section of the clutch stopper 35 issupported by an axis section 38 b (refer to FIG. 9) formed on the frame38, for example. The engaging section 35 b is urged to the gear section34 c. The clutch stopper 35 is urged with a spring (not depicted), forexample.

As depicted in FIG. 10(a), when the engaging section 35 b is positionedbetween the gears making up the gear section 34 c, the clutch stopper 35is arranged at the stopper acting position. As depicted in FIG. 10(b),when the first manipulating member 34 rotates, the engaging section 35 btemporarily runs on the gears making up the gear section 34 c and, as aresult, the clutch stopper 35 moves to the outside of the radialdirection of the first manipulating member 34. At this moment, theclutch stopper 35 is arranged at the stopper release position, uponwhich the clutch member 32 moves to the locked position.

As depicted in FIG. 9, the locking mechanism M may have two clutchstoppers 35 arranged at positions opposite to each other around theaxial line C1. The number of clutch stoppers 35 is not limited to two;namely, the number may be one or more than two.

The clutch stopper 35 is not limited to the example described above. Forexample, the clutch stopper 35 may be configured such that the clutchstopper 35 moves along with the rotation of the first manipulatingmember 34 in the axial line direction. Then, the clutch stopper 35 maybe moved between the stopper acting position at which the clutch stopper35 abuts on the clutch member 32 and the stopper release position atwhich the clutch stopper 35 comes away from the clutch member 32.

When the stopper by the clutch stopper 35 is released, the clutch member32 moves toward the locked position in the axial line direction and thenstops at the locked position by receiving the force of the spring 37.When the clutch member 32 is arranged at the locked position, the clutchstopper 35 abuts on the outer circumferential surface of the clutchmember 32, so that the clutch stopper 35 stops at the stopper releaseposition. As depicted in FIG. 6, the locking mechanism M has a secondmanipulating member 39 that can be manipulated by the user. Whenmanipulated by the user, the second manipulating member 39 returns theclutch member 32 to the unlocked position.

As described above, the clutch member 32 is movable between the lockedposition and the unlocked position in the axial line direction. Thesecond manipulating member 39 is a pushbutton that is supported so as tobe movable in the axial line direction, for example. In this case, whenpressed by the user, the second manipulating member 39 returns theclutch member 32 from the locked position to the unlocked positionagainst the force of the spring 37. The second manipulating member 39may not always be a pushbutton.

The wearing band 20 having the locking mechanism M described above isusable as follows, for example. The user presses the second manipulatingmember 39 so as to put the wearing band 20 into an unlocked state. Next,the user moves the movable section 30 in the extending direction or theretracting direction to adjust the size of the wearing band 20 in arough manner and then wears the wearing band 20 on his or her head. Atthis moment, the wearing band 20 is fixed on the head of the user by aforce of the elastic member 26 in a temporary manner. Then, the userrotates the first manipulating member 34 in the retracting rotationaldirection. Upon rotation of the first manipulating member 34, the firstmanipulating member 34 and the link member 31 are linked to each otherthrough the clutch member 32, the wearing band 20 getting in the lockedstate. As a result, when the rotation of the first manipulating member34 continues, the movable section 30 moves in the retracting direction(namely, the length of the wearing band 20 is shortened). In addition,the action of the stopper 33 engaged with the first manipulating member34 restricts the movement of the movable section 30 in the extendingdirection. Hence, even after the user stops the rotation of the firstmanipulating member 34, the movable section 30 does not move in theextending direction, thereby fixing the length of the wearing band 20.

As described above, when the movable section 30 moves in the retractingdirection, the locking mechanism M of the present embodiment switchesthe wearing band 20 from the unlocked state to the locked state. To bemore specific, the movable section 30 is configured so as to move in theretracting direction when the first manipulating member 34 moves in theretracting rotational direction and the locking mechanism M switches thewearing band 20 from the unlocked state to the locked state when thefirst manipulating member 34 moves in the retracting rotationaldirection. Hence, only one manipulation by the user for moving themovable section 30 in the retracting direction, in other words, only onemanipulation for moving the first manipulating member 34 in theretracting rotational direction can put the wearing band 20 into thelocked state.

The structure of the locking mechanism M having the functions describedabove is not limited to the examples described above. (1) For example,the locking mechanism M may not have the clutch member 32. In such acase, the locking mechanism M may move the first manipulating member 34or the link member 31 in the axial line direction so as to link (engage)these members with each other or release the linkage. (2) In addition,the locking mechanism M may not have the first manipulating member 34.In such a case, the user is able to move the movable section 30 directlyin the retracting direction and the extending direction. Then, thelocking mechanism M may put the wearing band 20 from the unlocked stateto the locked state when the movable section 30 moves in the retractingdirection. That is, when the movable section 30 moves in the retractingdirection, the locking mechanism M may transfer the link member 31 froma state in which the link member 31 is rotatable in both the retractingrotational direction and the extending rotational direction to a statein which the rotation in the extending rotational direction isrestricted. Such a structure can be realized by moving a stopperrestricting the rotational direction of the link member 31 relative tothe link member 31, for example. In such a case, the user may controlthe position of such a stopper by use of a manipulating member that canbe manipulated by the user. For example, in the unlocked state, thestopper may be arranged, by the manipulating member, at a position wherethe stopper does not engage with the link member 31. (3) Further, thefirst manipulating member 34 and the link member 31 may not alwaysarranged on the common axial line C1. For example, gear sections thatcan be engaged with each other may be individually formed at the outercircumferential section of the first manipulating member 34 and theouter circumferential section of the link member 31. Then, the firstmanipulating member 34 and the link member 31 may be relatively movablein the radial direction of the gears between a position at which thegear sections are engaged and a position at which the engagement of thegear sections is released. Besides, the rotational direction of thefirst manipulating member 34 may be restricted only to one direction.Such a structure also realizes the locked state of the wearing band 20by engaging the gear section of the first manipulating member 34 and thegear section of the link member 31 with each other. (4) Still further,the first manipulating member 34 may not always be a rotary member. Forexample, the first manipulating member 34 may be a slide member that ismovable in the radial direction of the link member 31 between a positionat which the first manipulating member 34 is engaged with the linkmember 31 and a position at which the first manipulating member 34 isnot engaged with the link member 31.

FIG. 11 and FIG. 12 are diagrams illustrating a variation to the lockingmechanism M. FIG. 11 is a cross-sectional view of a locking mechanismM1, illustrating a link member 131, a clutch member 132, and a frame138. FIG. 12 is a schematic view for describing a movement of the clutchmember 132, indicating a part of a gear section to be described later.In FIG. 11, components same as those of the locking mechanism M aredenoted by same reference symbols.

The link member 131 is formed with a gear section 131 b and the clutchmember 132 is formed with an engaging section 132 a for the engagementwith the gear section 131 b. The frame 138 is formed with a gear section138 a that is projected in the axial line direction and the clutchmember 132 is formed with an engaging section 132 b for the engagementwith the gear section 138 a. In other points, the link member 131 issimilar to the link member 31 described above and the clutch member 132is similar to the clutch member 32 described above. Further, the frame138 is similar to the frame 38 described above.

As with the clutch member 32, the clutch member 132 is movable in theaxial line direction between the locked position at which the clutchmember 132 engages with both the link member 131 and the firstmanipulating member 34 and the unlocked position at which the clutchmember 132 does not engage with one of the link member 131 and the firstmanipulating member 34. In FIG. 11, the clutch member 132 at theunlocked position is indicated as one example.

With the locking mechanism M1, the clutch member 132 moves between thelocked position and the unlocked position every time the secondmanipulating member 39 described above is pressed. In other words, whenthe clutch member 132 is pressed in the axial line direction by thesecond manipulating member 39 with the clutch member 132 being at thelocked position, the clutch member 132 moves to the unlocked position.When the clutch member 132 is pressed in the axial line direction by thesecond manipulating member 39 with the clutch member 132 being at theunlocked position, the clutch member 132 moves to the locked position.

As depicted in FIG. 12(a), a slant face 131 c is formed on every gear ofthe gear section 131 b of the link member 131. The slant face 131 c isformed such that, when the engaging section 132 a of the clutch member132 is pressed in the axial line direction toward the slant face 131 cof the link member 131, the clutch member 132 rotates in one direction(a D3 direction depicted in FIG. 12). The clutch member 132 is urgedtoward the side of the frame 138 with a spring (not depicted), forexample.

In the frame 138, two types of recessed sections having differentdepths, a recessed section 138 d and a recessed section 138 e are formedas recessed sections formed between the gears making up the gear section138 a. The recessed section 138 d is deeper than the recessed section138 e (hereafter, the recessed section 138 d is referred to as a lockedrecessed section and the recessed section 138 e is referred to as anunlocked recessed section). As depicted in FIG. 12(b), when the engagingsection 132 b of the clutch member 132 is at the deep locked recessedsection 138 d, the clutch member 132 is arranged at the locked position,engaging with both the link member 131 and the first manipulating member34. As depicted in FIG. 12(c), when the engaging section 132 b of theclutch member 132 is at the shallow unlocked recessed section 138 e, theclutch member 132 is arranged at the unlocked position and the clutchmember 132 does not engage with the first manipulating member 34. Itshould be noted that, as depicted in FIG. 12, two sizes of intervals ofthe gears of the gear section 131 b of the link member 131 arealternately arranged for the two types of the recessed sections 138 dand 138 e of the frame 138.

When the clutch member 132 is pressed by the second manipulating member39 with the engaging section 132 b of the clutch member 132 being at theunlocked recessed section 138 e, the clutch member 132 moves in the D3direction by the actions of the engaging section 132 a and the slantface 131 c of the link member 131 as depicted in FIG. 12(a).Subsequently, the clutch member 132 returns to the side of the frame 138(the side of the first manipulating member 34) by the urging force of aspring, for example. As a result, as depicted in FIG. 12(b), theengaging section 132 b of the clutch member 132 is mated with theadjacent locked recessed section 138 d and the clutch member 132 isarranged at the locked position. When the clutch member 132 is pressedby the second manipulating member 39 with the engaging section 132 b ofthe clutch member 132 being at the locked recessed section 138 d, theclutch member 132 moves in the D3 direction and, as depicted in FIG.12(c), the engaging section 132 b of the clutch member 132 is mated withthe adjacent unlocked recessed section 138 e and the clutch member 132is arranged at the unlocked position.

As described above, the HMD 1 has the main body 10 and the wearing band20. The wearing band 20 has the front support section 23 in the frontthereof. The front support section 23 is connected to the upper sectionof the main body 10. The main body 10 is movable relative to the wearingband 20, namely, the front support section 23 in the forward-backwarddirection. Consequently, the user is able to adjust the distance betweenthe display 11 and the eyes. In addition, by moving the main body 10forward, the user is able to look down with the HMD 1 mounted on thehead. For example, if the HMD 1 is used for a game play, the user isable to look at a game controller held in his or her hand.

FIG. 13 through FIG. 15 are diagrams illustrating structures that allowthe relative movements of the main body 10. In these diagrams, a firstguide 41 arranged on the wearing band 20 and a second guide 50 arrangedon the main body 10 are depicted. FIG. 13 is a plan view, FIG. 14 is aside view, and FIG. 15 is a cross-sectional view taken along line XV-XVdepicted in FIG. 14.

The wearing band 20 has a frame 40 shaped like a plate. The frame 40 hasa fixing section 40 a hat is fixed inside the front support section 23.The first guide 41 is arranged on the frame 40. To be more specific, theframe 40 has a support section 40 b that extends forward from the fixingsection 40 a and the first guide 41 is mounted on the support section 40b. The first guide 41 and the support section 40 b are arranged on theupper section of a housing 14 (refer to FIG. 1) that makes up the mainbody 10. The main body 10 has the second guide 50 on the upper sectionof the housing 14. The second guide 50 guides the movement of the firstguide 41 in the forward-backward direction.

As depicted in FIG. 15, the second guide 50 has a base 51. In oneexample of the second guide 50, the base 51 is a plate in shape. Thefirst guide 41 is arranged over the base 51, for example. The firstguide 41 may be arranged below the base 51. The base 51 has a side guidesections 51R and 51L on the right side and the left side of the base 51,respectively. The first guide 41 is arranged between the two side guidesections 51R and 51L. In other words, the side guide section 51R on theright side and the side guide section 51L on the left side arepositioned at the right side and the left side of the first guide 41,respectively, both extending along the rims of the first guide 41. Theside guide sections 51R and 51L and the base 51 are integrally formed ofmetal, for example.

The second guide 50 has guide rails that are formed separately from theside guide sections 51R and 51L and the base 51. The second guide 50 hasguide rails 53R and 53L on the right side and the left side thereof. Theguide rails 53R and 53L are arranged between the side guide sections 51Rand 51L and the rims of the first guide 41. The guide rails 53R and 53Lare formed of a resin such as plastic, for example. The first guide 41is also formed of a resin such as plastic, for example. The guide rails53R and 53L may be formed of metal. The guide rails 53R and 53L may beformed so as to sandwich the rim sections of the first guide 41 in theup-down direction as depicted in FIG. 15. This setup allows thereduction in the friction between the first guide 41 and the secondguide 50.

The guide rail 53L has a section 53 b (refer to FIG. 15) that receives aforce for pressing the guide rail 53L toward the rim of the first guide41 (hereafter referred to as a pressed section 53 b). This setup allowsthe contact of each of the guide rail 53R and the guide rail 53L to therim of the first guide 41, thereby consequently reducing a gap betweenthe rims of the first guide 41 of the frame 40 and the guide rails 53Land 53R. The guide rail 53L has a pressed section 53 a halfway in thelength direction thereof. Preferably, the guide rail 53L has two or morepressed sections 53 a arranged with intervals therebetween in the lengthdirection of the guide rail 53L.

As depicted in FIG. 14, the side guide sections 51R and 51L are walls inshape and are arranged along the guide rails 53R and 53L. The side guidesection 51L is formed with a hole 51 a from which the side surface ofthe guide rail 53L is partially exposed. The guide rail 53L is pressedtoward the rim of the first guide 41 through the hole 51 a of the sideguide section 51L. That is, a section that corresponds to the hole 51 aon the side surface of the guide rail 53L is the pressed section 53 a.The side guide section 51L may have two or more holes 51 a formed withintervals therebetween in the length direction of the guide rail 53L.

In a state before a fixing member 54 to be described later is fixed tothe second guide 50, the base 51 and the guide rail 53L are configuredsuch that the position of the guide rail 53L is slightly movable in theleft-right direction. A position in the left-right direction of theguide rail 53L is fixed by a member separate from the base 51 and theguide rail 53L. The member for fixing the position of the guide rail 53Lhas a section that touches the pressed section 53 b. With the guide rail53L touching the rim of the first guide 41, the position of the guiderail 53L in the left-right direction is fixed. It should be noted that“separate member” referred to above is a structural object (for example,a screw or a fixing member to be described later) or a material (forexample, adhesives) that could be moved separately from the base 51 andthe guide rail 53L before this separate member is used for fixing theguide rail 53L.

Thus, the second guide 50 has the base 51 having the side guide sections51R and 51L and the guide rail 53L positioned between the side guidesection 51L and the rim of the first guide 41. The guide rail 53L hasthe pressed section 53 a that can receive the force of pressing theguide rail 53L toward the first guide 41. The second guide 50 has amember separate from the base 51 and the guide rail 53L, this separatemember fixing the position of the guide rail 53L in the left-rightdirection relative to the base 51.

According to such a structure of the second guide 50, the followingmanufacturing method is made practicable. In other words, the guiderails 53R and 53L are arranged inside the side guide sections 51R and51L. Subsequently, the first guide 41 is arranged between the guiderails 53R and 53L. Then, with the pressed section 53 a of the left-sideguide rail 53L pressed toward the rim of the first guide 41, theposition of the guide rail 53L in the left-right direction is fixed by amember separate from the base 51 and the guide rail 53L. This setupallows the interval of the guide rails 53R and 53L to match the width ofthe first guide 41, thereby linearly moving the first guide 41 in theforward-backward direction.

As depicted in FIG. 14 and FIG. 15, the second guide 50 has the fixingmember 54 that is separate from the base 51 and the guide rail 53L. Thefixing member 54 has a pressing section 54 a. The pressing section 54 ais positioned inside the hole 51 a of the side guide section 51L andtouches the pressed section 53 a of the guide rail 53L described above.Further, the fixing member 54 has a fixing section 54 b that is fixed tothe base 51. According to the fixing member 54, a work of fixing theposition of the guide rail 53L is facilitated.

The fixing section 54 b is a plate in shape, for example. The pressingsection 54 a projects upward or downward from the rim of the fixingsection 54 b. In the examples depicted in FIG. 14 and FIG. 15, thepressing section 54 a projects upward from the rim of the fixing section54 b. The fixing member 54 has two or more pressing sections 54 aarranged with intervals therebetween in the length direction of theguide rail 53L. The fixing section 54 b is arranged on the lower surfaceof the base 51 and fixed to the base 51 as depicted in FIG. 15, forexample. The fixing section 54 b is welded to the base 51, for example.The fixing section 54 b may be deposited or adhered on the base 51. Itshould be noted that the guide rail 53L may be fixed to the base 51 byuse of an adhesive instead of the plate-shaped fixing member 54. Forexample, an adhesive may be charged from the hole 51 a into between theguide rail 53L and the side guide section 51L. In such a case, thesolidified adhesive functions as a fixing member.

As described above, the base 51 and the guide rail 53L are configuredsuch that the position of the guide rail 53L is slightly movable in theleft-right direction. For example, the base 51 is formed with a hole andthe guide rail 53L is formed with a projected section that mates withthis hole. In addition, the size of the hole in the left-right directionis slightly larger than that of the projected section of the guide rail53L. Consequently, before fixing the position of the guide rail 53L bythe fixing member 54, the position of the guide rail 53L is slightlymovable. It should be noted that, as depicted in FIG. 15, the side guidesection 51L has a holding wall section 51 b. The guide rail 53L issandwiched by the base 51 and the holding wall section 51 b in theup-down direction. Therefore, before fixing the position of the guiderail 53L by the fixing member 54, the guide rail 53L is held by the base51 in a slightly movable manner.

It should be noted that the side guide section 51R has generally thesame structure as that of the side guide section 51L except that thehole 51 a (refer to FIG. 14) is formed on the side guide section 51L.The side guide section 51R may also have the hole 51 a. In the exampledescribed above, the second guide 50 having the guide rails 53L and 53Rand the fixing member 54 is arranged on the main body 10 and the firstguide 41 is arranged on the wearing band 20. However, it is alsopracticable that the second guide 50 having the guide rails 53L and 53Rand the fixing member 54 is arranged on the wearing band 20 and thefirst guide 41 is arranged on the main body 10.

As depicted in FIG. 2, the wearing band 20 may have a front pad 25 infront thereof that touches the front side of the head of the user. Thefront pad 25 preferably has the cushion 25 b. The front pad 25 isarranged on the rear side of an upper section 23 b of the front supportsection 23. When the HMD 1 is worn on the head of the user, the wearingband 20 sandwiches the head of the user by the movable section 30described above and the front pad 25.

Preferably, the front pad 25 is supported such that the angle of thefront pad 25 in the forward-backward direction is adjustable. This setupallows changing of the angle of the front pad 25 in accordance with theshape and size of the head of the user.

FIG. 16 is a diagram illustrating an example of a structure that allowsthe adjustment of the angle of the front pad 25. FIG. 16(a) is a sideview of the front pad 25 with a part of the front pad 25 fractured. FIG.16(b) is a plan view of the front pad 25.

The front pad 25 has a bracket 25 a. The bracket 25 a is formed of amaterial that is comparatively high in stiffness such as plastic ormetal. In one example of the front pad 25, the bracket 25 a is a platein shape. The cushion 25 b mentioned above is mounted on the bracket 25a. The bracket 25 a has axis sections 25 c on the right side and theleft side thereof. The axis section 25 c is supported internally by thefront support section 23, for example. The axis section 25 c is locatedat the lower section of the front pad 25 in the side view. The uppersection of the front pad 25 is movable around the axis section 25 c inthe forward-backward direction. Consequently, the angle of the front pad25 can be adjusted.

As depicted in FIG. 16(b), the wearing band 20 has a manipulating member27 for the user to move the front pad 25. The manipulating member 27 isaccommodated inside the front support section 23. The manipulatingmember 27 is supported in a sliding manner in the left-right direction.The bracket 25 a has a pressed section 25 d that projects forward. Themanipulating member 27 has a pressing surface 27 a for pressing thepressed section 25 d. In accordance with the position of themanipulating member 27 in the left-right direction, the pressing surface27 a tilts such that the position of the pressed section 25 d of thebracket 25 a in the forward-backward direction changes. The manipulatingmember 27 has a manipulating section 27 b that exposes at the outersurface of the front support section 23 (refer to FIG. 3 and FIG.16(b)). According to such a structure, the user is able to change theangle of the front pad 25 by moving the position of the manipulatingmember 27 through the manipulating section 27 b in the left-rightdirection.

The main body 10 may have a light-blocking member for suppressing theexternal light from reaching the eyes of the user. The light-blockingmember is preferably formed of a material having flexibility. Thelight-blocking member is formed of elastomer, for example. FIG. 17 is aperspective view illustrating the main body 10 viewed from the rearside. As depicted in FIG. 17, the main body 10 has a side guard section61 as the light-blocking member that extends from the side section tothe rear side of the main body 10. The side guard section 61 blocks thelight from the right side and the left side of the HMD 1 when the HMD 1is in use. A rim 61 a of the side guard section 61 is preferablybending. This setup mitigates the uncomfortableness caused by touchingof the rim 61 a of the side guard section 61 onto the face of the userwhen the HMD 1 is worn on the head of the user.

As depicted in FIG. 17, the main body 10 has a frame 13. The frame 13has an opening 13 a on each of the right side and the left side thereof.In the deep part of the opening 13 a, a lens 12 and the display 11(refer to FIG. 2) are arranged. The user is able to view a video imageon the display 11 through this opening 13 a. Between the left-side andright-side openings 13 a, a recessed section 13 b opening backward anddownward is formed. When the HMD 1 is in use, the nose of the user ispositioned on this recessed section 13 b. A light-blocking member 62 maybe arranged also on this recessed section 13 b. The light-blockingmember 62 is arranged so as to cover the inside of the recessed section13 b when the main body 10 is viewed from the rear side. Thelight-blocking member 62 prevents the external light from reaching theeyes of the user through a gap between the inner surface of the recessedsection 13 b and the nose of the user when HMD 1 is in use.

The light-blocking member 62 is formed in a sheet shape that covers (orcloses) the recessed section 13 b, for example. The light-blockingmember 62 in a sheet shape such as mentioned above is formed of amaterial having flexibility, for example. The light-blocking member 62may be configured to be detachable with respect to the frame 13.Consequently, the position of the light-blocking member 62 inside therecessed section 13 b, in other words, the position of thelight-blocking member 62 in the forward-backward direction can bechanged in accordance with the size of the nose of the user. In theexample depicted in FIG. 17, the light-blocking member 62 is a sheet inshape and is formed with a slit that extends to a center section in theup-down direction. That is, the light-blocking member 62 has aright-side part 62 b and a left-side part 62 a. This setup prevents thelight-blocking member 62 from becoming an obstacle against thecomfortable wearing of the HMD 1 when the HMD 1 is in use. In addition,rims 62 c of the right-side part 62 b and the left-side part 62 a arepreferably bending. This setup mitigates the uncomfortableness caused bytouching of the rim 62 c of the light-blocking member 62 onto the noseof the user when the HMD 1 is worn on the head of the user.

The present invention is not limited to the embodiment described above;namely, changes and variations may be made as required. For example, theangle adjustment mechanisms for a light-blocking member, the guides 41and 50, and the front pad 25 have been described herein; however, theHMD related with the present invention may not have these mechanisms.

1. A head-mounted display comprising: a main body in which a display isbuilt; a wearing band extending from the main body to a rear side andhaving a shape enclosing a head of a user as a whole; a right-sideextending section configured to make up a right-side part of the wearingband; a left-side extending section configured to make up a left-sidepart of the wearing band; a movable section configured to make up a partof a rear side of the wearing band, link a rear section of theright-side extending section with a rear section of the left-sideextending section, and be movable relative to the right-side extendingsection and the left-side extending section in a retracting direction inwhich the length of the wearing band is decreased and in an extendingdirection in which the length of the wearing band is increased; alocking mechanism capable of switching the wearing band between anunlocked state in which movements of the movable section in theextending direction and the retracting direction are allowed and alocked state in which a movement of the movable section at least in theextending direction is restricted; and a first manipulating memberarranged on the movable section and positioned at a part of the rearside of the wearing band, the first manipulating member being able to bemanipulated by the user, wherein the movable section is configured to beurged at least in the retracting direction in the unlocked state andmoved in the retracting direction when the first manipulating membermoves in a first direction, and the locking mechanism switches thewearing band from the unlocked state to the locked state when the firstmanipulating member moves in the first direction
 2. The head-mounteddisplay according to claim 1, wherein the wearing band has an elasticmember that causes a force acting on the movable section in theretracting direction
 3. The head-mounted display according to claim 1,wherein the elastic member is arranged along each of the right-sideextending section and the left-side extending section, thereby pullingthe movable section in the retracting direction 4.-5. (canceled)
 6. Thehead-mounted display according to claim 1, wherein the wearing bandincludes a link member that rotates in a third direction when themovable section moves in the retracting direction and rotates in afourth direction when the movable section moves in the extendingdirection, and the locking mechanism allows movements of the link memberin both the third direction and the fourth direction in the unlockedstate and restricts a movement of the link member in the fourthdirection in the locked state
 7. The head-mounted display according toclaim 6, wherein the locking mechanism includes a one-way member that isallowed to rotate in a first direction when the link member rotates inthe third direction and is restricted from rotating in a seconddirection when the link member rotates in the fourth direction, and thelocking mechanism links the link member with the one-way member in thelocked state and releases the linkage between the link member and theone-way member in the unlocked state
 8. The head-mounted displayaccording to claim 7, wherein the locking mechanism links the linkmember with the one-way member when the one-way member moves in thefirst direction
 9. The head-mounted display according to claim 7,wherein the link member and the one-way member are arranged on a commonaxial line, and the locking mechanism includes a clutch member thatmoves between a locked position at which the clutch member engages withboth the link member and the one-way member and an unlocked position atwhich the clutch member does not engage with at least one of the linkmember and the one-way member
 10. The head-mounted display according toclaim 8, wherein the one-way member is the first manipulating member 11.The head-mounted display according to claim 7, further comprising: asecond manipulating member configured to release the linkage between theone-way member and the link member, the second manipulating member beingable to be manipulated by the user
 12. A head-mounted displaycomprising: a main body in which a display is built; a wearing bandextending from the main body to a rear side and having a shape enclosinga head of a user as a whole; a right-side extending section configuredto make up a right-side part of the wearing band; a left-side extendingsection configured to make up a left-side part of the wearing band; amovable section configured to make up a part of a rear side of thewearing band, link a rear section of the right-side extending sectionwith a rear section of the left-side extending section, and be movablerelative to the right-side extending section and the left-side extendingsection in a retracting direction in which the length of the wearingband is decreased and in an extending direction in which the length ofthe wearing band is increased; a locking mechanism capable of switchingthe wearing band between an unlocked state in which movements of themovable section in the extending direction and the retracting directionare allowed and a locked state in which a movement of the movablesection at least in the extending direction is restricted; and a firstmanipulating member arranged on the movable section and positioned at apart of the rear side of the wearing band, the first manipulating memberbeing able to be manipulated by the user, wherein the movable section isconfigured to move in the retracting direction when the firstmanipulating member moves in a first direction, and the lockingmechanism switches the wearing band from the unlocked state to thelocked state when the first manipulating member moves in the firstdirection
 13. The head-mounted display according to claim 12, whereinthe wearing band has, on the movable section, a link member that engageswith both the right-side extending section and the left-side extendingsection and cooperatively operates with a movement of the movablesection relative to the right-side extending section and the left-sideextending section, the link member rotates in a third direction when themovable section moves in the retracting direction and rotates in afourth direction when the movable section moves in the extendingdirection, and the locking mechanism allows movements of the link memberin both the third direction and the fourth direction in the unlockedstate and restricts a movement of the link member in the fourthdirection in the locked state.